DOI

https://doi.org/10.48717/f3jz-d268

Project

EW025

Title

EW025A

Abstract

In a group environment, the transition from the galaxy dark matter halos to the group halo reveals the merging and evolutionary history of the group. Cuspy and cored dark matter density profiles are difficult to distinguish for galaxies across all redshifts. B1359+154 is a six-image strongly lensed radio-loud quasar that provides a unique opportunity to probe the inner density profiles of the lensing galaxy halos, truncation radius, and the compact group halo environment. We request high-resolution and high-sensitivity EVN-eMERLIN observations to image the lensing arc at 1.7 GHz, and to resolve the core-jet structure of the radio source at 5 GHz. Taking advantage of the high lensing magnification, the source can potentially be resolved down to sub-parsec physical scales at redshift 3.235. The constraints from the lensing arc and image subcomponents will tightly constrain the matter density profile in the lensing galaxy group. Additionally, these data will verify the core-jet structure of the high-redshift radio source suggested by previous observations, and could give estimates of the positional shift of a radio jet in the early universe over the past two decades.